Conveyor dishwashers are known in the art. Dishes enter one end dirty and exit an opposite end clean. A desirable attribute of such dishwashers is adjustable conveyor speed. For example, a relatively dirty load of dishes may require "more" washing than a relatively clean load. In such a case, it would be nice to run the conveyor at a relatively slow speed to effectively increase the washing time. on the other hand, with a relatively clean load, it would be nice to run the conveyor at a relatively fast speed to conserve resources. Moreover, since groups of relatively clean dishes and relatively dirty dishes may be interspersed with one another, it would be nice to adjust conveyor speed without interrupting operation of the dishwasher.